I just threw them away.
They represented an incredible opportunity for learning. With enough analysis, I could put together blow-by-blow accounts of my successes and failures, trace root causes, spot trends and common errors and correct them.
But I'll never do this work. The ore is plentiful but not especially rich. And the limiting factor, as always, is not available opportunities but time to pursue them. This is a useful thing I could do, but there will always be so many more useful things that it'll never happen, and there's no point in pretending that it will.
And the scribbled notebooks are just the tip of the iceberg. I have an Evernote file full of notes of nearly every meeting I've been in, not only documenting what was decided but also my impressions of the parties, alternatives considered and rejected, next steps, slow-burn things I'm thinking about. Writing up my notes is always my first instinct after anything happens.
With very few exceptions, I've never looked at them. By the time that it's needed, that information is almost always superseded by newer, and still easily-accessible, data - and to the extent that it's not, I remember it. And to the extent that something is lost, usually it's relatively unimportant. Satisficing matters, here, not optimising.
If I'd known then how I'd treat all this data now, I wonder if I'd have spent less time recording, and more time acting?
The best advice I've heard for organising physical possessions is, "Put it in the first place you'll look". That is, switch your perspective to your future self looking for this item, and don't go for the most logical place to put it, go for the most logical place to retrieve it from.
I think it makes sense to apply that, also, to information. "What should you record? Not what you think you need to write, but what the future you will need to read."
Writing more is not only wasted effort, it also boosts the noise that you'll need to later extract some kind of signal from. And it provides an opportunity, and an excuse, to be lazy. Instead of processing the information right now, making a decision, acting on that decision, and throwing the information away, you can feel good that you've gotten everything down, when actually you've just made work for later.
It's digital hoarding: the idea that it's better to have something and not need it than need it and not have it, when in fact the reverse is true.
I can think of two exceptions to this harsh rule:
* Notes for spaced repetition. This information doesn't need processing because it's already processed. Re-reading them refreshes your memory.
* Mementoes: diary entries and related material. This material doesn't need processing because there's no processing to do. It serves, instead, as a memory anchor for a time you might want to revisit.
But Mary Schmich put all of this much more succintly:
"Keep your old love letters. Throw away your old bank statements."